The present invention relates to a small and flat motor, and an apparatus, e.g. a portable apparatus, using the same motor. More particularly, it relates to an impact-resistant motor construction, in which terminals used for mounting the motor to the apparatus are disposed on a bottom face of the motor.
Recently, a small and flat motor to be mounted to a portable apparatus has been required to have impact-resistance in addition to small and thin profile as well as light in weight. A vibration motor, among others, used in a cellular phone is required to be impact resistant as high as 10,000-20,000 G. On the other hand, a xe2x80x9cslimmed-down versionxe2x80x9d has been always required.
Several methods have been adopted to increase the impact resistance, such as respective elements is thickened to bear an impact-load, an entire construction has high rigidity, respective components are rigidly attached with each other, and the like. For the portable apparatus, however, a sturdily built version does not satisfy market demand because the xe2x80x9csturdily builtxe2x80x9d increases not only its own weight but also load to its supporting structure. This phenomenon goes against the xe2x80x9cslim-downxe2x80x9d requirement and fails to satisfy the impact-resistance requirement.
The impact-resistance requirement of 10,000-20,000 G is the severest for the motor having ever confronted. An effective conventional technique to deal with this requirement is thus hardly found. The inventors of the present invention, therefore, analyze which part is broken, and what kind of stress is applied, in order to meet the requirement.
In the case of an outer-rotor-type flat motor with cores, they find the following weak points: radial and thrust bearings, a coupling section between a bearing supporter and a motor base, coupling section of a shaft, a coupling section between a motor and an apparatus, and a magnet. Loads applied to respective sections can be divided into radial load and thrust load. On top of these loads, impact in a rotating direction exists; however, it can be neglected because it affects a little.
The present invention addresses the problem discussed above and aims to provide a slimmed down motor having an improved impact-resistance, and an apparatus using the same motor.
The motor of the present invention comprises the following elements:
a rotor;
a stator assembly facing the rotor;
a motor base including:
a base;
a bearing supporter for supporting a bearing vertically with respect to the base;
a stator supporter for being mounted with the stator assembly and being substantially concentric with the bearing supporter;
metal terminals disposed around the bearing supporter, and the lower faces of the terminals being exposed from a bottom face of the base.
An inner wall of the stator assembly is fit on and fixed to an outer wall of the stator supporter. Further, a stator stopper protruded from the base is prepared. The stopper and a lower end face of the outer wall of the stator assembly are closely faced with each other in an axial direction.
The apparatus of the present invention comprises the following elements:
a motor;
a board on which the motor is mounted; and
a driver for driving the motor which has the structure discussed above.
These structures allow the motor to be smaller, thinner and light weighted. The apparatus using this motor can be also smaller, thinner and light weighted, and yet, excellent impact-resistance is obtainable.